1. Field of the Invention
The present invention relates to a data processing apparatus for performing input, update, and output processing operation for a file.
2. Description of Related Art
A conventional data processing apparatus including a computer stores files in a disk unit, for example, and updates the files in accordance with input record data. Companies in various industrial sectors are introducing computers, and the contents of files and input records are different depending on the industry sectors. Even in a same industrial sector, a line of business generally differs depending on the specific nature of the particular business. Accordingly, the contents of files, and records to be input or to be output from the files, are variously different.
In order to deal with the situation described above, in a conventional data processing apparatus, a system is designed to correspond to various particular input records, files, and output records. Accordingly, programs are designed and prepared individually to deal with the particular input records, files, and output records. In each case, the program is designed in a program language. More specifically, in response to data input from an input section, a data processor performs a set of processing operations such as reading a record to be updated from a file, performing arithmetic and logical operations for the record, and rewriting the record in the file. A program must be described in a program language so as to execute the set of processing operations each time a record is input.
As described above, in a conventional data processing apparatus, various programs must be prepared dedicated for each line of business of various industrial sectors. In designing a file management system for managing files, an update program for updating a file must be designed. A structure of a record in a file and word positions in a record are fixedly allocated in a memory. Furthermore, the respective files have different record structures. For this reason, a program for updating a record in a file in accordance with an input data, must be designed to be adapted for the particular record structure. Such program design is troublesome and time consuming. In addition, each firm or company generally requires a large number of different types of files, and therefore is obliged to design, individually, a large number of programs corresponding to the respective files.
Furthermore, each firm uses a large number of types of business slips or forms, including, for example, order-acceptance slips, sales slips, purchase slips, and transfer slips of traveling-expense statement of accounts, credit slips, and the like. Throughout the following description, such slips, forms, records, etc. are referred to as "slips" for ease of designation. In general, each firm or company has its own input record formats for the above various types of slips. Accordingly, an input processing program must be individually designed in correspondence with the various types of slips of the respective users. Therefore, a great deal of labor and time is required to design the individual system satisfying the requirements of each user.
Furthermore, in each program is described to have a set of procedures of inputting, updating, and outputting of a file. Therefore, when the contents of files or input or output records are updated for a change of the line of business and the like, a large number of modifications are required for each program. Such modifications for an entire system are not easily accomplished, and in some cases, a system must be redesigned.